The invention relates generally to incinerators, and more particularly to continuous controlled movement of combustible refuse into, and through, a combustion chamber by a rotating auger conveyor.
The use of an auger to convey combustible refuse through the combustion cycle results in very accurately controlled movement of refuse through the combustion chamber, in comparison to presently used rotary kiln incinerators. However, if the auger flight is integral with the auger shaft, with no spacing between them, the passage of air through the refuse is restricted, and it is necessary to introduce air into the combustion chamber through the auger shaft and/or auger flight. Also, it is necessary to supply cooling means for the auger flight as well as for the auger shaft. As a result, this type of auger is expensive to manufacture, requiring much welding, and equally expensive to repair or replace parts.
The auger construction used in the present invention overcomes these disadvantages by incorporating an annular space between the auger shaft and auger flight. Thus air can move freely in the combustion chamber except for the space occupied by the auger shaft, and air can be introduced solely through the combustion chamber walls rather than through the auger shaft and flight assembly.
With such an arrangement, the auger flight can be very simply constructed of single sheets of heat resistant material, requiring little or no welding. Different materials can be used for various sections of the auger flight to correspond to the heat to which the auger flight will be exposed in that section of the incinerator. The placement of a section of the auger flight is also made correspondingly easier and less expensive.
Therefore, one object of the present invention is to provide an incinerator which includes a rotatable conveyor having spiral flights to continuously feed refuse into and through the combustion chamber wherein complete combustion can be effected without the need of supplying air through the rotatable conveyor shaft or spiral flights.
It is a further object of this invention to provide an incinerator with a rotatable conveyor having spiral flights, which flights are of simple construction and do not require a cooling means for normal operation, and which can be easily repaired or replaced.
A still further object of this invention is to provide a means for preventing smoke and combustion gases from being emitted from the open inlet to the combustion chamber of this incinerator.
Yet another object of this invention is to provide a means of selectively pre-heating combustion air admitted to the combustion chamber, so that the hottest air is admitted at the inlet end of the chamber to quickly heat incoming refuse, and cooler air is admitted to the exhaust end of the chamber to effect more complete combustion.
Still another object of this invention is to provide a means for moving the combustible refuse through the combustion chamber at a slower rate at the outlet end of the chamber than at the inlet end of the chamber, to effect better combustion of particulate smoke at the outlet end of the chamber, and to compensate for the reduction in volume of the refuse during combustion.